hard to say exactly. a good friend of mine uses kumho victoracers in his M coupe and he drives to each event (some are 150miles each way) with the r comps. he told me he generally gets 50-60 runs before the tires need to be replaced.

but keep in mind his tires have basically no tread from the factory and his car is a lot heavier... lastly he is a very fast driver (national level) so he gets every ounce of traction out of the tires.

me personally, I plan on going to toyo ra-1 which should last me nearly 1 full season ~20 events or less. I also plan on driving to event with the r-comps on.

now if you use just regular street V/Z rated tires, then it will last about a season if you're lucky.